From 0c78251d2c9da76fd9ae171aad472544f50ca533 Mon Sep 17 00:00:00 2001 From: Robert Fancsik Date: Thu, 9 Dec 2021 17:04:46 +0100 Subject: [PATCH] Fix Typedarray.slice fastpath when the content type is matching This patch fixes #4888. JerryScript-DCO-1.0-Signed-off-by: Robert Fancsik robert.fancsik@h-lab.eu --- .../ecma-builtin-typedarray-prototype.c | 22 +++++++++++-- .../es.next/regression-test-issue-4888.js | 31 +++++++++++++++++++ 2 files changed, 50 insertions(+), 3 deletions(-) create mode 100644 tests/jerry/es.next/regression-test-issue-4888.js diff --git a/jerry-core/ecma/builtin-objects/typedarray/ecma-builtin-typedarray-prototype.c b/jerry-core/ecma/builtin-objects/typedarray/ecma-builtin-typedarray-prototype.c index 52f72fadf0..f89c833216 100644 --- a/jerry-core/ecma/builtin-objects/typedarray/ecma-builtin-typedarray-prototype.c +++ b/jerry-core/ecma/builtin-objects/typedarray/ecma-builtin-typedarray-prototype.c @@ -1628,14 +1628,30 @@ ecma_builtin_typedarray_prototype_slice (ecma_value_t this_arg, /**< this argume return ECMA_VALUE_ERROR; } - JERRY_ASSERT (new_typedarray_info.offset == 0); - src_buffer_p += relative_start << info_p->shift; if (info_p->id == new_typedarray_info.id) { // 22.2.3.23. Step 22. h-i. - memcpy (dst_buffer_p, src_buffer_p, count << info_p->shift); + + if (JERRY_LIKELY (new_typedarray_info.offset == 0)) + { + memcpy (dst_buffer_p, src_buffer_p, count << info_p->shift); + } + else if (count >= new_typedarray_info.offset) + { + uint32_t byte_shift = (uint32_t) (1 << info_p->shift); + + while (count) + { + memmove (dst_buffer_p, src_buffer_p, byte_shift); + + dst_buffer_p += byte_shift; + src_buffer_p += byte_shift; + + count--; + } + } } else { diff --git a/tests/jerry/es.next/regression-test-issue-4888.js b/tests/jerry/es.next/regression-test-issue-4888.js new file mode 100644 index 0000000000..60dc2d7f45 --- /dev/null +++ b/tests/jerry/es.next/regression-test-issue-4888.js @@ -0,0 +1,31 @@ +// Copyright JS Foundation and other contributors, http://js.foundation +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +var ab = new Int8Array(20).map((v, i) => i + 1).buffer; +var ta = new Int8Array(ab, 0, 10); +ta.constructor = { + [Symbol.species]: function (len) { + return new Int8Array(ab, 1, len); + } +}; + +var tb = ta.slice(); + +for (let e of ta) { + assert(e === 1); +} + +for (let e of tb) { + assert(e === 1); +}